Clean Harbors Expands Board of Directors with Appointment of Edward G. Galante

Former Exxon Mobil Executive is Tenth Outside Director on 11-Member Board

Norwell, MA – September 22, 2010 – Clean Harbors, Inc. (NYSE: CLH), the leading provider of environmental, energy and industrial services and hazardous waste management services throughout North America, today announced the appointment of Edward G. Galante to the Company’s Board of Directors.

Mr. Galante, 59, retired in 2006 after more than 30 years with Exxon Mobil. Most recently he served as a Senior Vice President and member of the Management Committee. His principal responsibilities included the worldwide Downstream business: Refining & Supply, Fuels Marketing, Lubricants and Specialties and Research and Engineering. He also was responsible for Exxon Mobil’s corporate Public Affairs and Safety, Health and Environmental activities.

“In a career defined by excellence at every level, Ed Galante brings a unique set of skills and attributes that we believe will enable him to make a significant contribution to the Clean Harbors board,” said Alan S. McKim, Chairman and Chief Executive Officer. “His 34 years of industry experience will be a valuable asset, particularly as we expand the Energy & Industrial component of our business and further capitalize on growth opportunities in the petroleum industry. Complementing this industry knowledge, Ed has the corporate governance experience to ably represent our shareholders. He understands the issues that are critical to our growth and success as a company, and shares the commitment to corporate values that are central to our organization. I am honored to welcome him as our tenth outside director.”

Mr. Galante’s appointment expands the Clean Harbors board to 11 members. He will serve on the Corporate Governance Committee. He will be a Class I director whose term of office will expire at Clean Harbors’ 2011 annual meeting of shareholders.

Mr. Galante joined Exxon Company, U.S.A. marketing in 1972 where he held a variety of assignments in retail engineering, technical services, industrial sales, product line coordination and terminal operations. He also held assignments in Corporate Planning, Supply, Downstream Planning and Refining, where he became manager of Exxon's Baton Rouge, Louisiana, Refinery in 1988.

In 1992, Mr. Galante was named Chief Executive and General Manager of Esso Caribbean and Central America in Coral Gables, Florida. Three years later he became Executive Assistant to the Chairman of Exxon Corporation before being appointed Chairman and Managing Director of Esso (Thailand) Public Company Limited in Bangkok in 1997. He was named Executive Vice President of Exxon Mobil Chemical Company in Houston in 1999.

A native of Inwood, New York, Mr. Galante received his Bachelor of Science degree in civil engineering from Northeastern University. He serves as a Vice Chairman of Northeastern’s Board of Trustees and as an Executive-in-Residence in its College of Business Administration. He also serves on the Board of Directors of Praxair, Inc. (NYSE: PX), where he sits on the Compensation & Management Development and the Governance & Nominating committees; Foster Wheeler Ltd. (NASDAQ: FWLT), where he sits on the Audit and Governance and Nominating committees; Junior Achievement Worldwide; and the United Way Foundation of Dallas.

About Clean Harbors

Clean Harbors is the leading provider of environmental, energy and industrial services and hazardous waste management services throughout North America. The Company serves more than 50,000 customers, including a majority of the Fortune 500 companies, thousands of smaller private entities and numerous federal, state, provincial and local governmental agencies.

Headquartered in Norwell, Massachusetts, Clean Harbors has more than 175 locations, including over 50 waste management facilities, throughout North America in 36 U.S. states, seven Canadian provinces, Mexico and Puerto Rico. The Company also operates international locations in Bulgaria, China, Sweden, Singapore, Thailand and the United Kingdom. For more information, visit www.cleanharbors.com.

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